Ever wonder why most major highway tunnels prohibit tanker vehicles containing flammable liquids (except, in some cases, during certain designated hours)? Tanker drivers can blame the Caldecott Tunnel Fire of 1982 for such regulations. A drunk San Leandro bookkeeper hit the curb in the northern bore, stalling the car and triggering the wreck of a gasoline tanker and an apocalyptic fire that claimed seven lives. The scars from the fire were still visible on the tunnel walls until fairly recently. – Murilee Martin